Reversing a vehicle while towing a trailer can be challenging for many drivers, particularly for drivers that drive with a trailer on an infrequent basis or with various types of trailers. Systems used to assist a driver with backing a trailer frequently estimate the position of the trailer relative to the vehicle with a sensor that determines a hitch angle. The accuracy and reliability of this hitch angle estimation can be critical to the operation of the backup assist system. It is also understood that reliable hitch angle estimation can be useful for additional vehicle features, such as monitoring for trailer sway.